Abstract

The realization of quantum memory using warm atomic vapor cells is appealing because of their commercial availability and the perceived reduction in experimental complexity. In spite of the ambiguous results reported in the literature, we demonstrate that quantum memory can be implemented in a single cell with buffer gas using the geometry where the write and read beams are nearly copropagating. The emitted Stokes and anti-Stokes photons display cross-correlation values greater than 2, characteristic of quantum states, for delay times up to 4 μs.

Spectral scans using tunable etalons of the Stokes (top) and anti-Stokes (bottom) channels. The cell temperature was 37 °C, the write and read pulse durations were 2 μs, and the detunings 1.2 and 1.085 GHz, respectively.

Measured intensity correlation between Stokes and anti-Stokes photons as a function of the delay between the write and read 1 μs long pulses for the 10 Torr Ne cell. The upper curve is for the etalon set to transmit anti-Stokes photons, while the lower curve is for the etalon tuned to transmit the collisional anti-Stokes fluorescence. The error bars denote the calculated 1σ deviation values.